Torque South

The car is an S4 NA with a TurboII engine, and belongs to my neighbor. He did the whole swap himself. He's only 17, and it's his first car. It actually starts and runs pretty good. It wouldn't idle unless the vaccuum hose was unplugged from the Idle Air Control. Then it would boost 7 psi and run hard (he says). Vaccuum was decent too. I suspected a bad IAC (or BAC, whatever it's called), so we put back the one from his NA setup. Now it idles, but a little too high (1100-1400), and only pulls 10 inches of vaccuum. It also has no exhaust yet (he's shopping for one), could that cause a high idle? Thanks for looking, this kid needs all the 2nd gen advice he can get right now. Also, the temp gauge reads erratic (shoots up when you shut off the car, we don't trust it). Could this be due to the NA gauge cluster?

VIDEO:

http://www.youtube.com/watch?v=Y5RV_4CzseE

HAILERS

If he used the TURBO harness on the engine and did not make adjustments to that harness, that could be PART of the problem.

If he's using a Turbo ECU in conjunction with a non turbo pressure sensor, that could be part of the idle problem.

There's no vacuum line to the BAC at all.

If he's boosting to 7psi in the driveway, then I think the vacuum/pressue lines on the turbo are routed wrong to the wastegate. That shouldn't happen at all.

EDIT: Or did you mean the air feed line to the BAC from the turbo outlet duct??? Must a meant that.

Look at the backside of the turbo INLET duct. Are there any open holes there? A large hole is for the air bypass valve (BOV) and then there's a smaller hole for a silver check valve that has a hose that runs to the other side of the engiine after it connects to a metal hard line.

MaczPayne

iTrader: (5)

Vacuum should increase as the idle speed increases. I suspect a vacuum leak somewhere in the system.

What did the compression test tell you about the motor?

MidnightOwl

I used a Turbo harness on my car, and rewired it to work with my car. It's not too bad, but I'm fairly technically minded and it wasn't a big deal to me. Just some solder and wire and the FSM.


Here is some of the wiring, as well as some other TII swap stuff:
http://www.rotaryresurrection.com/2n...to_turbo2.html

You'll need the FSM for the wiring chart:
http://www.rx7city.com/techconnect.htm

It's about halfway down the page. I can't recall what the harness names are, but they are like FEM01 and FEM02 or something. HAILERS has posted how to wire it up several times, but I haven't searched for it to link for you. Those two places should get you going. The temp gauge problem will be remedied after you wire it up correctly. Also, I bet your idiot lights are all lit up too.

Torque South

Thanks for the responses. He is using the TurboII harness in the engine bay only. It plugs into the ECU, and the body harness is still NA. What modifications does he have to make to the harness?

Also, I guess I meant the tubo outlet duct to the BAC. He had the fat short hose disconnected so it can idle. Now it's reconnected to the NA BAC. And it was boosting 7 psi under load, not on the driveway.

He also had the factory pop-off valve in the intake disconnected because the vaccuum line wouldn't reach. I told him that it's causing a leak and that vaccuum opens the valve when the throttle plate closes. Trying to help him figure this out, thanks for your assistance. Maybe I'll take more videos of it later and post it.

Has not been compression tested, but "seems" healthy. Got the whole setup for $500.

Good info. And yes, the idiot lights are all lit!

MidnightOwl

Yup, you need to get wiring on that harness.

HAILERS

Yes. It's starting to make some sense now. What is happening now is he has 12vdc going to pin 2B on the ECU AND backfeeding to the pressure sensors output wire, making the ECU think he's in boost. Not too hard to take care of. Only two wires immediatley involved. There are two ORANGE elect plugs on that engine (EM) harness just inside the passengers foot well. You need to attend to those two wires.

In the jpg attached of SOMEONE elses harness laying on the floor, to the left you see a LARGE grommet and two ORANGE plugs. One to the left of the harness, one to the right. These are the plugs I'm talking about.

Look at the attached jpg of the plug. Half that plug is from the Front harness. The other half is from his new engine (EM) harness. THAT is the half that needs attending to. Also notive how some wire colors have ( ) around them. THOSE are peculiar to the TURBO cars.

So what I've witten/colored/pointed to, are the two wires that need attending to. What is going on with your car, is, the BrR (brown/red) wire from the boost sensor is connecting to a wire in the front harness that is BW (black/white). That black white wire goes diretly to a fuse inside the car. Not good. You NEED to cut that
BrR wire about two to three inches back from the plug and cap it's end off. That alone will solve a couple of problem. Now no 12vdc will be going to the pin 2B boost sensor input at the ECU. Good.

The other wire is BrB or possibly on some cars pure BLACK instead. Do the same. Cut it back from the plug about two inches back and cap it off. Now you won't be sending a gnd signal to the alt relay in the CPU causing the Waring light to be on all the time.

HAILERS

Hmmm. How did he know he was boosting/??????????

Anyway, since he put a turbo EM harness on the non turbo car, he now has no electrical connections to the small, two wire plug on the back side of the alternator. They exist on the non turbo EM harness but not the turbo EM harness. You have to run two NEW wires to the plug shown in my jpg above.

See on the F side of that plug where the wire colors are BW and WB? One above the other? Yes. He needs to run the two new wires from the alternator to those locations. He COULD just splice them to the two wires you just cut in my post above on the EM side of that plug. That's why we left two to three inches back from the plug before we cut that BrR and BrB wires, so you could attach wires to them.

HAILERS

He's also missing the signal from the water temp sender on the engine that also goes thru the orange plugs.

Torque South

Thanks a lot. He has an aftermarket boost gauge and an FCD (fuel cut defender). I warned him about the possible danger from the FCD. He saw the 7 psi under load when he was stepping on it. Thankfully, due to the vaccuum leaks/other issues he was unable to boost too high (he says) even with the intake and open exhaust, so (we think) the motor is still ok. I figured that this forum would be a great source for him, sure enough.

HAILERS

The YW wire in the plug shown in the other post, is the water temp signal.

Stop here for a moment: There are two orange plugs. One called X-15 that has fifteen pins/sockets in it. The other plug is orange also and is X-16 and has 13 pins/sockets in it.

Continure: So, what you NEED to do, is move that YW wire from the EM half of ........X-15, to the other ornage plug called X16. You'll remove a LgB wire in the corner of X-16 and install that YW wire in its place.

A jpg showing both orange plugs is attached where I TRIED to point to what needs to happen.

I won't say a thing about how if he left the non turbo harness in the car and attached to the turbo engine, how it would have been easier/simpler. Nope, won't say anything about that.

HAILERS

So. You 1. Gave up.

2. My words and jpg were too vague.

3. Your celebrating MLK day and have better things to do.

Torque South

LOL, your time and effort is appreciated. I had to work on MLK day, and simply haven't gotten around to responding because I have my own Rx-7 that breaks something every single day (literally). Latest project - remove cluster and re-solder tachometer. Anyways, this info will be very helpful to Eric and I am printing it out now from work. Thanks a lot!

Torque South

And btw I think he still has the NA harness, unless he cut it during the swap. But I'll leave it up to him, he needs to look at all this info and see what he's going to do.

Torque South

Thanks everyone for your help. They are still working on this, been reviewing the info and installing a new exhaust. It now has a nice full Racing Beat exhaust so it's a lot quiter and smoother. Now the question is:

Is the idle high (1500 rpm) because of the harness needing to be modified, or does that only affect the gauges?

Also the O2 sensor is disconnected, cannot seem to find the receiving connector on the harness anywhere. But as far as I understand that should just keep it in closed loop and running a bit too rich. Am I wrong?

Torque South

I meant open loop of course...

Thanks to all the helpful info posted, this project has made a little progress.

He got the idiot lights on the dash to shut off by modifying the wiring to the alternator as instructed in the link. Unfortunately they came back on when he altered the harness some more, I'll find out exactly what he did very shortly so I can ask the question correctly.

Torque South

Ok, so after he cut the two wires inside the car that were for the alternator on the N/A setup, the idiot lights started working perfect. Very happy about that. However, when the wires ran from the alternator, traced and connected, all the lights come back on? Why is this happening? I will try to take a pic of the connector and wires' current state soon so you can get a better idea.

HAILERS and MidnightOwl, your contributions have been a priceless asset to this project, and the car has come a long way considering a bunch of rookies are working on it for the first time.